1. Field of the Invention
The present invention is generally related to switches in which a moveable contact is attached to a contact carrier and, more particularly, to a switch in which the moveable carrier is provided with fingers between which the moveable contact is disposed.
2. Description of the Prior Art
As is well known to those skilled in the art, moveable contacts are usually attached to a contact carrier in a manner which permits the contacts to move, or wobble, relative to the contact carrier. The purpose of the variable motion is to assure proper contact between the moveable contact and stationary contacts across which the moveable contact provides an electrical bridge when actuated. If the moveable contact is rigidly attached to the contact carrier, the moveable contact could move into electrical connection with one of the stationary contacts and not the other. This type of misalignment could result in electrical arcing if only a slight contact force is provided against one of the stationary contacts or, alternatively, the electrical connection between the stationary contacts might not be made at all if the misalignment is severe.
The variable movement of the moveable contact relative to its contact carrier can be provided in several ways. One technique, which will be described in greater detail below, provides a moveable contact member that has an annular portion shaped to fit over a post attached to the contact carrier. The post is provided with an end portion that is shaped to permit the moveable contacts to be assembled over the end of the shaft and then rotated into its operating position. Another switch design that provides a variable attachment of the moveable contacts with respect to the contact carrier uses a clip to attach the two components together in a manner that provides the relative movement of the moveable contacts both with respect to the carrier and with respect to the stationary contacts.
U.S. Pat. No. 3,646,491, which issued to Puetz on Feb. 29, 1972, discloses a moveable contact structure for a large size electric switch that is arranged so that the contacts of the switch may be readily inspected. The contact structure includes a moveable contact retainer that has apertured ears and the base of the switch which supports the stationary contacts includes support posts, which, when the switch is disassembled to inspect the contacts, are available to act as a fulcrum for the shank of a screwdriver when the tip of the screwdriver is inserted into the apertures.
U.S. Pat. No. 3,448,226, which issued to Mading et al on Jun. 3, 1969, discloses a compact electrical contact block with electrically isolating bridging contacts. The block is of the type used in manually operable pushbutton assemblies. It includes an insulating housing and a reciprocating actuable plunger which supports two electrically isolated bridging contacts. Spring means and a sliding contact support provide for wear allowance and contact pressure.
U.S. Pat. No. 4,045,635, which issued to Pursnani et al on Aug. 30, 1977, describes as electrical switch construction that has a housing provided with an actuator for causing movement of a moveable switch blade relative to a over travel compensating fixed switch blade. The fixed switch blade is secured to a rigid terminal carried by the housing. It is provided with an extension thereof that is disposed in the path of movement of the fixed switch blade in order to limit movement thereof in one direction.
U.S. Pat. No. 3,991,290, which issued to Bayles et al on Nov. 9, 1976, discloses an anti-rock preventing means for use with electric switch contacts. The device is intended for use with electrical switches of the sort that are capable of carrying high amperage currents, especially under short circuit conditions. It is provided with a ferromagnetic U-shaped yoke piece around the contacts and an armature mounted on the moveable contact carrier in position to be attracted by the magnetic force created in the yoke when current flows through the contacts.
U.S. Pat. No. 3,953,697, which issued to Teichert on Apr. 27, 1976, discloses a dual fulcrum switch in which the switch includes a housing which carries a first contact defining a first fulcrum and has an elongated electrically conductive lever blade disposed in overlying relationship. It carries a second contact from one end thereof for normally engaging the first contact. A third contact is carried from the opposite end of such blade and it is moveable through a predetermined path to engage a fourth contact carried from the housing and defining a second fulcrum.
U.S. Pat. No. 3,922,627, which issued to Shepher Nov. 25, 1975, describes a double-throw single-pull switch that comprises a resilient moveable contact arm fixed at one end and carrying a first contact on one surface of the free end thereof for engagement with a mating stationary second contact. The contact arm carries on its opposite surface a third contact positioned intermediate the fixed and free ends thereof for engagement with a mating stationary fourth contact. Means are provided for selectively applying force to the contact arm intermediate its free and fixed ends for moving the contact arm to make and break the first and second contacts and to make and break the third and fourth contacts.
The attachment of moveable contacts to a contact carrier assembly in such a way that the moveable contacts are variable in position to provide the necessary wobble for achieving the purposes described above normally necessitates a contact carrier having a shape which necessitates complex and expensive molding techniques in order to manufacture the contact carrier. In addition, known designs of contact carriers and moveable contacts attached thereto require numerous parts and expensive assembly processes. It would therefore be beneficial if a switch could be made which simplifies the design of contact carrier and facilitates assembly of the moveable contacts to the contact carrier while maintaining all of the desirable attributes of a contact carrier with moveable contacts described above.